Prestressed all-metal roof structure



Sept. 9, 1947.. G. M. RAPP PRESTRESSED ALL-METAL ROOF STRUCTURE FiledMarch 19, 1946 4 Sheets-Sheet l INVENTOR O Sept. 9, 1947. RAPP 2,427,021

PRESTRESSED ALL-METAL ROOF STRUCTURE INVENTOR GEORGE M. RAPP fi?i bus/TORNY'EY Sept. 9, 1947. RAPP PRESTRESSED ALL-METAL ROOF STRUCTURE Fi ledMarch 19, 1946 4 Sheets-Sheet :s

INVENTOR 4Q GEORGE M RAPP I gm Sept. 9, 1947.

G. M. RAPP 2,427,021

YRESTRESSED ALL-METAL ROOF STRUCTURE Filed March 19,- 1946 4 Sheet-Sheet4 INVENTOIL GEORGE M. RAPP ATTORNEY Patented Sept. 9, 1947 PRESTRESSEDALL-METAL ROOF STRUCTURE George M. Rapp, New Haven, Conn., assignor toJohn B. Pierce Foundatian, New York, N. Y..

a corporation of New Yo Application March 19, 1946, Serial No. 655,625

20 Claims. (01. 1081) The invention relates to pre-stressed arched roofstructures.

An object of the invention is to provide a. roof structure embodying theassembly of mutually correlated component sub-structures individuallycomprising a resilient slender member which is pre-stressed to bowed orarched configuration, the resulting roof structure being particularlyadapted for building construction wherein low costs of material and oflabor, lightness of weight and durability of assembly are paramount.Preferably, such pre-stressed resilient slender member is of metal,notably-steel, thereby attaining enhanced structural strengths, andco-ordinating remaining elements of the roof structure also of metal,whereby resistance against fire is also attained.

In general, embodiments of the invention comprise a plurality of sets ofindividual substructures, each set of sub-structures spanning theopening tobe covered by the roof structure, each such sub-structurecomprising a slender member of resilient material, preferably of metal,pre-stressed to bowed formation, combined with co-ordinating parts forsupporting such prestressed bowed member and maintaining the same in itssaid pre-stressed bowed status, the plurality of sets of suchsub-structures respectively interconnected in seriatim overlappingrelation with respect to one another completing the'expanse of the roof.Usually each such set comprises two such sub-structures which wheninstalled are conjoined, the pre-stressed members comprising componentparts of a stable and load supporting structure, which may have generaltruss or triangular or general curvilinear or arch-like configuration,the abutting juxtaposed face portions of the conjoined pair ofsubstructures at or adjacent the ridge line of the roof being secured toone another.

More specifically, pursuant to the most.preferred forms of theinvention, the roof comprises a plurality of pairs of suchsub-structures of sulmtantlally duplicate construction, the pre stressedmember of each sub-structure being in the form of a corrugated sheetmember of metal, serving as the primary roof member, the corrugations ofsuch corrugated member extending from the cave line to the ridge line ofthe roof, and one or more pairs of tension elements such as lengths ofpipe, rods or wires, respectively, pivotally connected to the inner faceof each such corrugated member. Each of these tension elements isprovided with a tum-buckle,

sleeve nut or the like for adjusting and prethe central ridge member.

stressing the corrugated member to its desired bowed configuration.Suitable ridge members are provided for spanning the joints at theabutting juxtaposed face portions of such pairs of such sub-structuresat the ridge of the roof. The thrusts or outward forces caused by thetruss or arch-like shape are carried by tension ties secured at theiropposite ends at or adjacent to the eave lines. Suitable vertical strutmembers support these tension ties at their mid-span points, which theyconnect to the ridge line of the roof; The roof thus is completed byduplicates of such pairs of sub-structures disposed in mutually seriatimoverlapping relationship with one another.

The invention afiords low cost of material in that ample factor ofsafety is attained by enhanced mechanical strengths imparted by thepre-stressed member, enabling relatively light materials to be utilized.Savings in labor costs are attained in that each such sub-structure maybe assembled at a central location and shipped to the site of erection.Desirably, each such sub-structure is shipped "fiat, that is to say, thecorrugated or like member being in flat status, the operation ofpre-stressing such member being carried out at the site of erection byturning the turn-buckles or sleeve nuts to prestress the respectivemembers to the desired uniform arch configuration.

Further features and objects of the invention will be more fullyunderstood from the following detailed description and the accompanyingdrawings, in which:

Fig. 1 is a perspective of a preferred form of roof constructionembodying the invention, a

pair of sub-structures being shown in substantial entirety, andindicated portions of adjacent seriatim overlapping sets of duplicatepairs of sub-structures.

Fig- 2 is a detail sectional view on line 2-2 of Fi 1.

Fig. 3 is a detail section Fig. 1.

Fig. 4 is a detail view of the parts shown in Fig. 3, as appears fromline 4-4 of Fig. 3.

1 view on line 3-3 of Fig. 5 is a perspective view of the left handsub-structure of the roof shown in Fig. 1, and its triangular support.

Fig. 6 is a top plan view of the sub-structure shown in Fig. 5, with theaddition of a portion of Fig. 7 is. a bottom plan view of Fig. 6.- Fig.8 is a detail sectional view on line 8-8 of Fig. 5, however, showing thesub-section in flat,

1. e. non-stressed status.

Fig. 9 is a sectional view of Fig. 1, taken transversely of a pair ofcorrelated sub-structures. supported in triangular relation with respectto the eave lines of opposite walls of the building.

Fig. 10 is a detail sectional view of a central portion of Fig. 9, on anenlarged scale.

Fig. 11 is a detail sectional view on line il-H of Fig. 9, on anenlarged scale.

Fig. 12 is a detail sectional view through the non-stressed roofelement, showing a variant form or corrugation.

Fig. 13 is a detail section through the nonstressed roof element,showing another variant form of corrugation.

Referring to the preferred embodiment of the invention illustrated inFigs. 1, and 9 of the drawings, the roof structure comprises a pinralityof pairs of duplicate, conjoined sub-structures, the roof beingcompleted by duplication of such pairs of conjoined sub-structures inseriatim overlapping relation, as is indicated in Figs. 1 and 7. 20designates generally the pair of conjoined roof sub-structures shown inentirety in Fig. 1. 2!, 2|, indicates fragmentarily a pair of suchduplicate conjoined sub-structures extending to the right of the pair20, 29; 22, 22. similarly indicates fragmentarily a pair of suchduplicate conjoined sub-structures extending to the left of the set 29,20. Each pair of roof substructures abut one another at their juxtaposedfaces, i, e., centrally of the roof, a ridge member serving to close theline of jointing thereat, such ridge members being arranged in seriatimoverlapping relation, as appears more fully hereinafter,

Each roof sub-structure comprises primarily a slender resilient member23, preferably of sheet formation and of steel or the like, which issubjected to pre-stressing; preferably, also, such member 23 iscorrugated, the apices of the corrugations extending from the cave lineto the central ridge line. Desirably, such pre-stressing is eifected, asshown, by means of a pair of stress rods 24, 24, one end of each rodbeing pivotaily fulcrumed with respect to the inner face of the member22, respectively adjacent the cave and ridge end portions of the member,tension being applied to such pair of rods 24, 24, as by a turn-buckleor sleeve nut 25, to thus pre-stress the corrugated member 22 undertension to its desired bowed configuration.

Specifically, the pivoted end of each of the pair of stress rods foreach member 22 is pivotally fulcrumed in a clevis-like element. Theclevis-like element at the cave: line of each member 22 is designated22; it is shown welded to a face 21a of one leg of the L-shaped plate21, the face 21b of the other leg of the L-shaped plate being spotwelded to the inner apices of the corrugations of the member 22, asshown in Figs. 1, 2, 5, 9, and 11. The pivoted ends of the cooperatingstress rods 24 adjacent the ridge line of each member 22, are fulcrumedin the clevislike elements designated 22, a face of each of which, seeFigs. 1, 5, 9 and 10, is welded to the inner face of the member 22adjacent its ridge line. The two clevis-like elements 28, 22 of eachmember 22. are welded, as appears in Figs. 5 and 8, to a face 22a of oneleg of the L-shaped plate 23, and the face 23b of such L-shaped plate iswelded to the inner apices of the member 22. I

Intermediate the cave line and the ridge line of each member 22, and onthe inner face there- 4 of are plates 20, 30, shown of flattenedU-shape, which are spot welded to the inward apices .of the corrugationsof each member. Each plate 20 is provided with transverse closed-endedslots 30a, 20a, through which pass the respective stress rods 24, 24,24, 24.

Upon joining the pair of correlated sub-structures spanning a givenportion or the roof, the abutting juxtaposed faces of the L-shapedplates 29, 29, are rigidly connected to one another, as by bolting,which may be performed on location.

Desirably, the joint at the ridge line of the roof and the adjacentridge portions of each pair of conjoined sub-structures are sheathed bya ridge member, preferably an arcuated ridge member 2|, as shown inFigs. 1, 5, 9 and 10, such ridge member being rigidly secured to theunderlying ridge portions of such pair of substructures, preferably byself-tapping screws, indicated at 32, 32, in Fig. 10.

Each pair of sub-structures, as shown in the illustrated preferredembodiment, is supported in triangular spanned relation relative to thewalls of the building or other construction, as by the assembly ofhorizontal beams in turn carrying at their centers vertically extendingplates in turn supporting the ridge portions of the sub-structures. Asillustrated in Figs. 1, 5 and 9, and fragmentarily in Fig. 10, suchtriangularly confilgurated assembly includes the horizontal extendingbeams 33, shown of U- shape. The opposite eave ends 33a of each of suchbeams are shown secured to plates 34, 34, as by means of bolts orequivalent indicated at 35, such plates 34, 34, being secured to theupper faces of the building walls indicated at 35, 35. As shown, suchplates 34, 34, are each secured to the underfaces of the respectiveclevislike elements 26, 26, as by welding, and in turn secured by bolts36, 36, to the respective walls 37, 31, of the building. Desirably. asshown in Fig. 2, a buttress of wood or steel indicated at 38 secured tothe top of each wall 35, is interposed, with which buttress theassociated clevisiike element 28 is secured, as by the bolts 28. Suchbuttress 23 serves as a cushion of limited yield, advantageous in thecircumstance when the roof structure is subjected to substantialstresses, as under :high wind conditions.

It will be observed from Figs. 1, 2 and 9, that the free ends of theeave disposed L-shaped plates 21 of the seriatim pairs of conjoinedsubstructures butt one another. The joints thus formed may be protectedso as to accomplish a weather-seal by bolted or screw-attached spliceplates.

Associated with such horizontal extending beam 22 are the verticallyextending supporting plates 33, see Figs. 1, 5, 9 and 10, shown carriedat their lower ends by the beams 22. Such plates 28, as indicated, maybe of U-shape, and secured at the lower ends of the respective beams 22by bolts. as indicated at 40 in Fig. 9. To the upper end of eachsupporting plate 23, as shown in Figs. 9 and 10, is secured a bracket4|.

As indicated in Figs. 1, 5 and 9, the extent of pre-stressing of eachroof member ,22 is determined by the total span of the roof, theindividual roof members 22 being bowed to substantially uniform archconfiguration. In general, such arch is of low arcuate configuration,the plurality of sets of conjoined sub-structures forming a resultingroof of low pitch.

When shipped from the factory. or other location of pre-assemoly, and/orwhen placed in relation with the storage, each sub-structure isdesirably in flat status, as is illustrated in Fig. 8, that is to say,the turn-buckle 25, or equivalent being in slack stress rods 24, 24, theroot element 23 being thus in flat status.

Upon bowing the respective roof members 23 to the desired pre-stressedstatus, as indicated in Figs. 3 and 4, a yoke bolt 42 may be employed tointerconnect each rod length 24 with the lower flange of the U-shapedplate 30, and tightened by nuts 43. Desirahly, shims, indicated at 44 inFig.3, are interposed between the flange of the plate 38 and the freeends of the yoke bolt, and tightened by nuts 44.

From the above'it is apparent that the resulting roof structure may beconstituted of relatively light weight reason of the high mechanicalstrength imparted by the pre-stressed roof members 24 and theirrespective pairs 24, 24, 01 stress rods in tension, the roof structurepossesses a. high factor of safety.

The roof structure attained by the embodiment illustrated in Figs. 1-through 11 is of particular application for farm service structures,suchas barns. sheds, poultry and hog houses, com cribs, etc., for whichpurpose the pre: stressed corrugated sheet members 23 the primary roofelements.

In Figs. 1 throughll the members 23 are indicated of uniform arcuatecorrugations; however, other forms of,.,corrugation for the members 23may be employed. Figs. 12 and 13 illustrate variant types of corrugationapplicable to the invention. In Fig. 12 theresilient sheet member hasrectangular trough-like corrugations,

parts, and nevertheless byserve as whereas theresilient sheet member,shown in Fig. 13 the corrugations are of frusto-tapering formation.

Non-corrugated sheets ofresilient metal such as steel or of othersuitable material may also be.

employed for the members 23, as will; be apparent. In such applicationof the invention the outer surfaces of the non-corrugated members may becovered by conventional sheet roofing,

material, secured by asphaltic or like waterrepelling andweather-resisting cement.

I claim:

1. A roof sub-structure comprising in combination a member of resilientsheet material; correlated slender elements fulcrumed at theirrespective one ends to an inner faceof said sheet memher; and meansrespectively connected to the respective opposite ends of said-slenderelements for drawing the stated points of fulcrum of said slenderelements to thereby subject said sheet member to tension and therebycausing said sheet member to assume a bowed configuration.

2. A roof sub-structure comprising in combination a member of resilientcorrugated sheet material; correlated slender elements fulcrumed attheir respective one ends to an inner face "of said sheet me her; andmeans respectively connected to th respective opposite ends of saidslender elements for drawing the stated points of fulcrum of saidslender elements to thereby subject said sheet member to tension andthereby causing said sheet member to assume a bowed configuration.

bination a member of resilient sheet material,

said sheet member being corrugated and having its peaks of corrugationsextending from the cave line upwardly of the roof; correlated slenderelements fulcrumed at their respective one ends to an inner face of saidsheet member; and means respectively connected to the respectiveopposite ends of said slender elements for drawing the stated points offulcrum of said slender elements to thereby subject said sheet member totension and thereby causing said sheet member to assume a bowedconfiguration.

' 4. A roof sub-structure comprising in com bination a member ofresilient corrugated metallic sheet material; fulcrumed at theirrespective one ends to an inner face of said sheet member; and meansrespectively connected to the respective oppositeends of said slenderelements for drawing the stated points of fulcrum of said slenderelements to thereby subject said sheet member to tension and therebycausing said sheet member to assume a bowed configuration.

5. A roof ub-structure comprising in combination a member of resilientmetallic sheet material, saidsheet member being corrugated and havingits peaks of corrugations extending from the eave line upwardly of theroof; correlated slender elements fulcrumed at their respective one endsto an inner face of said sheet member; and means respectively connectedto the respec tive opposite ends 'of said slender elements for drawingthe stated points of fulcrum of said slender elements to thereby subjectsaid sheet member to tension and thereby causing said sheet member toassume a bowed configuration.

6. A roof sub-structure comprising in combination a member of resilientsheet material; correlated slender elements fulcrumed at theirrespective one ends to an inner face of said sheet member; meansrespectively connected to the respective opposite ends of said slenderelements for drawing the stated points of fulcrum of said slenderelements to thereby subject said sheet member to tension and therebycausing said sheetmember to assume a bowed configuration; and means ofgeneral triangular configuration for supporting said roof substructure.

7. A roof sub-structure comprising in combination a member of resilientcorrugated sheet material; correlated slender elements fulcrumed attheir respective one ends to an inner face of said sheet member; meansrespectively connected .to the respective opposite ends of said slenderelements for drawing the stated points of fulcrum of said slenderelements to thereby subject said sheet member to tension and therebycausing said sheet member to assume a bowed configuration; and means ofgeneral triangular configuration for supporting said roof sub-structure.

8. A roof sub-structure comprising in combination a member of resilientsheet material, said sheet member being corrugated and having its peakof corrugations extending from the cave line upwardly of the roofcorrelated slender elements fulcrumed at their respective one ends to aninner face of said sheet member; means respectively connected to therespective opposite ends of said slender elements for drawing the statedpoints-of fulcrum of said slender elements to thereby subject said sheetmember to tension and thereby causing said sheet member to assume abowed'conflguration; and means of general triangular conflguratlon forsupporting said roof sub-structure.

9. A roof sub-structure comprising in combination amemberof resilientcorrugated metallic sheet material; correlated slender elementsfulcrumed at their respective one ends to an inner 'face .of saidsheet-member; means respectively correlated slender elements 7 connectedto the slender elements for drawing the stated points or fulcrum of saidslender elements to thereby subject said sheet member to tension andthereby causing said sheet member to assume a bowed configuration; andmeans of general triangular configuration for supporting said rootsubstructure.

10. A roof sub-structure comprising in combination a member of resilientmetallic sheet material, said sheet member being corrugated and havingits peaks of corrugations'extending from the eave line upwardly oi theroof; correlated slender elements iulcrumed at their respective one endsto an inner face of said sheet member; means respectively connected tothe respective opposite ends of said slender elements for drawing thestated points of fulcrum of said slender elements to thereby subjectsaid sheet member to tension and thereby causing said sheet member toassume a bowed configuration; and means of general triangularconfiguration for supporting said roof substructure.

11. A roof structure formed of a plurality of sets of conjoined roofsub-structures, each roof sub-structure comprising in combination amember of resilient sheet material; correlated slender elementsfulcrumed at their respective one ends to an inner face of said sheetmember; means respectively connected to the respective opposite ends ofsaid slender elements for drawing the stated points of fulcrum of saidslender elements to thereby subject said sheet member to tension andthereby causing said sheet member to assume a bowed configuration; meansof general triangular configuration for supporting said roofsubstructures; and ridge enclosing means secured to the resulting roofstructure adjacent and extending over the juxtaposed portions of therespective sets of conjoined roof sub-structures.

12. A roof structure formed of a plurality of sets of conjoined roofsub-structures, each roof sub-structure comprising in combination amember of resilient corrugated sheet material; correlated slenderelements iulcrumed at their respective one ends to an inner face of saidsheet member; means respectively connected to the respective oppositeends of said slender elements for drawing the stated points of fulcrumof said slender elements to thereby subject said sheet member to tensionand thereby causing said sheet member to assume a bowed configuration;means of general triangular configuration for supporting said roofsub-structures; and ridge enclosing means secured to the resulting roofstructure adjacent and extending over the juxtaposed portions of therespective sets of conjoined roof substructures.

13. A roof structure formed of a plurality of 'sets of conjoined rooisub-structures, each roof sub-structure comprising in combination amember of resilient sheet material, said sheet member being corrugatedand having its peaks of corrugations extending from the eave lineupwardly of the roof; correlated slender elements fulcrumed at theirrespective one ends to an inner face of said sheet member; meansrespectively connected to the respective opposite ends of said slenderelements for drawing the stated points of fulcrum of said slenderelements to thereby subject said sheet member to tension and therebycausing said sheet member to assume a bowed configuration; means ofgeneral triangular configuration for supporting said rooisub-structures; and ridge enclosing means serespective opposite ends oisaid cured to the resulting roof structure adjacent and extending overthe juxtaposed portions of the respective sets of conjoined roofsub-strucures.

14. A roof structure formed of a plurality of sets of conjoined roofsub-structures, each rooi sub-structure comprising in combination amember of resilient corrugated metallic sheet material; correlatedslender elements fulcrumed at their respective one ends to an inner faceof said sheet member; means respectively connected to the respectiveopposite ends of said slender elements for drawing the stated points offulcrum of said elongated elements to thereby subject said sheet memberto tension and thereby causing said sheet member to assume a bowedconfiguration; means of general triangular configuration for supportingsaid roof sub-structures; and ridge enclosing means secured to theresulting roof structure adjacent and extending over the juxtaposedportions of'the respective sets of conjoined roof sub-structures.

15. A root structure formed of a plurality of sets of conjoined roofsub-structures, each roof sub-structure comprising in combination amember of resilient metallic sheet material, said sheet member beingcorrugated and having its peaks of corrugations extending from the eaveline upwardly of the roof; correlated slender elements fulcrumed attheir respective one ends to an inner face of said sheet member; meansrespectively connected to the respective opposite ends of said slenderelements for drawing the stated point of fulcrum of said slenderelements to thereby subject said sheet memberto tension and therebycausing said sheet member to assume a bowed configuration; means ofgeneral triangu; lar confiiguration for supporting said roofsubstructures; and ridge enclosing means secured to the resulting roofstructure adjacent and extending over the juxtaposed portions of therespective sets of conjoined roof sub-structures.

16. A roof structure formed of a plurality 0! sets of conjoined roofsub-structures, each roof sub-structure comprising in combination amember of resilient slender material; correlated slender elementsfulcrumed at their respective one ends to an inner face of said slendermember;

means respectively connected to the respective opposite ends of saidslender elements for drawing the stated points of fulcrum of saidslender elements to thereby subject said slender member to tension andthereby causing said slender member to assume a bowed configuration; andmeans of general triangular configuration for supporting said roofsub-structures.

17. A roof structure formed of a plurality of sets of conjoined roofsub-structures, each roof sub-structure comprising in combination amember of resilient corrugated slender material; correlated slenderelements fulcrumed at their respective one ends to an iner face of saidslender membenmeans respectively connected to the respective oppositeends of said slender elements for drawing the stated points of fulcrumof said slender elements to thereby subject said slender member totension and thereby causing said slender member to assume a bowedconfiguration; and means of general triangular configuration iorsupporting said roof sub-structures.

18. A roof structure formed of a plurality of sets of conjoined rootsub-structures, each roof sub-structure comprising in combination amember of resilient slender material, said slender member beingcorrugated and having its peaks of corrugations extending from the caveline upwardly of the roof; correlated slender elements fulcrumed attheir respective one ends to an inner face of said slender member; meansrespectively connected to the respective opposite ends of said slenderelements for drawing the stated points of fulcrum of said slenderelements to thereby subject said slender member to tension and therebycausing said slender member to assume a bowed configuration; and meansof general triangular configuration for supporting said roofsub-structures.

19. A roof structure formed of a plurality of sets of conjoined roofsub-structures, each roof sub-structure comprising in combination amember of resilient corrugated metallic slender material; correlatedslender elements fulcrumed at their respective one ends to an inner faceof said slender member; means respectively connected to the respectiveopposite ends of said slender elements for drawing the stated points offulcrum of said slender elements to thereby subject said slender memberto tension and thereby causing said slender member to assume a bowedconfiguration; and means of general triangular configuration forsupporting said roof sub-structures.

20. A roof structure formed of a plurality of sets of conjoined roofsub-structures, each roof sub-structure comprising in combination amember of resilient metallic slender material, said slender member beingcorrugated and having its peaks of corrugations extending from the eaveline upwardly of the roof; correlated slender elements fulcrumed attheir respective one ends to an inner face of said slender member meansrespectively connected to the respective opposite ends of said slenderelements for drawing the stated points of fulcrum of said slenderelements to thereby subject said slender member to tension and therebycausing said slender member to assume a bowed configuration; and meansof general triangular configuration for supporting said roofsub-structures.

GEORGE M. RAPP.

